Boring machine for cylindrical electrotypes



March 23, 1954 G, w. BUNGAY 2,672,772

BORING MACHINE FOR CYLINDRICAL ELECTROTYPES Filed Sept. 20, 1950 2 Sheets-Sheet 1 INVENTOR. 6 5mm: 1M BUNGAY A TTORNEYS March 23, 1954 G W. BUNGAY 2,672,772

BORING MACHINE FOR CYLINDRICAL ELECTROTYPES Filed Sept. 20, 1950 2 Sheets-Sheet 2 INVEN TOR. za/Paif M Bu/vG/IY BY TTORNfI 5 Patented Mar. 23, 1954 BORING MACHINE FonoYLINDRioAL ELECTROT PES George W. Bungay, New York, N. Y-., as'signor to Electrographio Corporation,

corporation of Delaware Application September 20, 1950-, Serial No. 185,793

(c1. "ii-62) 1 Claim.

The present invei'itionrelates to a novel and improved boring machine for interiorly' finishing cylindrically curved electrotypes of varying dimensions.

Objects and advantages of the invention will be set forth in part hereinafter and in part will be obvious hereirom, or may be learned by prac tice with the invention, the same being realized and attained by means of the inst'rumentalities and combinations pointed out in the appended claims. a

The invention consists in the novel parts, constructions, arrangements, combinations and im= provements herein shown and described The accompanying drawings, referred to herein and constituting a part hereof, illustrate one the description, serve to of the invention.

Of the drawings:

Figure l is a fragmentary side elevation of a typical and illustrative embodiment of a plate boring machine in accordance with the present invention;

Figure 2 is a fragmentary top plan View of a travelling cylindrical work holder forming a portion of the mechanism shown in Figure 1;

Figure 3 is a vertical sectional view taken on the line 5-3 of Figure 1;

Figure 4 is a fragmentary sectional view taken a on the line i l of Figure 3; and

Figure 5 is a perspective detail showinga work holding clamp movable circumferentially of the Work holder for securing an electrotype plate by one of its edges.

The boring machine of the present invention is particularly adapted for [main connection with New York, N. Y, a

the production of curved or cylindrical electrotypes such as are used in the rotary printing of high grade magazines, particularly where such plates are produced by the centrifugal casting of the backing metal onto a, previously curved shell, after accuracy such as is needed for of rotary magazine printing.

In accordance the highest class tions, while the other pair are of substantially equal axial extent and are adapted to be power between the first clamps ad acent the other edge of the work holder may be varied to receive two plates of the same size, or of different sizes, or a doublespread plate. Pressure is applied to one edge of the plate by operation of the gear reduction means so as to force the plate circumferentially of the work holder towards the other clamp and also forcing the curved plate into firm contact with the concave face of the Work holder so that as the work holder moves under the rotarycutter, metal is removed from the interior of the plate to finish the plate accurately to a fixed predetermined thickness, at the same time that its interior is rendered cylindrical.

It will be understood that the foregoing general description and the following detailed description as well are exemplary and explanatory of the invention but are not restrictive thereof.

Referring now in detail to the present preferred and illustrative embodiment of the present invention as shown in the accompanying drawings, the boring machine is shown as adapted to receive and operate on one or two single page plates of the same or different size, each of which may be as large as a semi-cylinder, a two page wide, or double-spread plate, or fractional page plates, all of the plates being of the same external diameter and to be bored to the same thickness.

The bed of the machine comprises a heavy casting 8 on the upper portion of which are formed bed-ways l adapted to receive and guide the slide member I2 on which is rigidly held the work holder l4. At one end of the and projecting over the bedways therefrom is a spindle housing iii in which is mounted a motor driven spindle is carrying at its outer end a rotary boring tool 18 mounted on a tool carrying disc driven tioned to cut on the desired radius as the work holder i4 moves the plate to be bored beneath the revolving boring tool l8. Suitable motor driven feed screw means 22 cooperate with the work holder 14 so as to move the work holder and plate past the boring tool in either direction.

The work holder I4 is mounted rigidly on the slide member [2 by means of its downwardly divergent, integral feet 24 which are secured to the slide member 12 by means of the cap screws 26, and the work holder 14 is of suflicient strength so as to form a rigid, substantially unyielding support for the curved electrotype positioned in the concave portion of the work holder. The ends of the work holder are preferably open, unobstructed and chamfered so that there is no danger of the face of the electrotype being scratched or marred as it is positioned in or removed from the work holder.

Along one edge of the work holder l4, it is provided with a plurality of, preferably four, circumferentially extending arcuate slots 32 having parallel sides which form guideways for the arcuate clamping members to engage one edge of one or two plates 30. These clamping members preferably comprise a short arcuate steel plate 34 having its exterior fare curved to conform to the concave interior of the work holder 14 and formed with a straight edge 36 which is adapted to form an abutment for one of the straight edges of the plate 30.

--For variably positioning and positively holding each of the two clamping plates 34 in the desired circumferential position of the work holder If, each of the clampin plates 34 is securely fas- [0 and spaced machine bed B by the spindle and posipair of clamps adjacent one I accurately of the desired thickness.

tened to a pair of guide members 38 by means of the screws 40, each of these guide members 38 being T-shaped in cross section and dimensioned and positioned to have a close fit with the arcuate slots 32 so that the straight edge 36 of each clamping plate 34 always remains parallel to the axis of the work holder 14. The lower ends of the guide members 38 are preferably extended so to overlie the solid portion of the work holder l4, and each of the guide members is provided with a heavy radially movable, inwardly sprin pressed locking pin 42 adapted to enter one or another of a series of uniformly spaced pin holes 44 formed in the outer side of the work holder and arranged in a circumferential series, so that the work holding clamp as a whole may be variably positioned and securely locked in any desired circumferential position merely by withdrawing two of the pins 42 and sliding the plate 34 circumferentially of the work holder until the desired position has been reached. The holes 40 are preferably arranged about an inch apart so as to minimize the travel of the clamping member for the opposite edge of the plate 30, and the holes 44 serving for one of the plates 34 are preferably accurately alined with those for the other plate 34.

Along the other edge of the work holder l4 are provided a similar series of guideways 32, preferably circumferentially alined with the first series, and a similar pair of clamping plates 34 which are adapted to be powerfully moved toward and away from the other parallel edge of the plate 33, and these plates 34 are each secured to a pair of guide members 38' which are preferably constructed similar to the guide members 38, except that the outer end portion of the guide members 38 is formed as an arcuate rack 46 which is adapted to mesh with and be moved by the pinion ends 48 of a shaft 50.

Shaft 50 is journaled at its ends in bearing blocks 52 secured to the outer face of the work holder l4 and adjacent the outer sides of a pair of slots 32 and near its central portion is provided with a worm reducing gear 54 which is meshed with a self-locking worm 56, journaled in a plate 58 which is secured to the bearing blocks 52. Hand crank 60 fast to the worm shaft 56 serves to turn the worm and thereby provides a means for powerfully moving and automatically locking both guide members 38' to force one of the plate clamping members 34 powerfully toward its opposite clamping members as the clamping edges 36 engage the parallel edges of the electrotype 30.

The clamping plates 34 are preferably of less thickness than the finished thickness of the electrotype plate 30 so that there is no danger of the cutting tool l8 cutting into the clamping plates 34 as it bores the interior of the electrotype. The clamping plates 34 are arranged in two opposing pairs so that two different plates, of the same or different size, may be engaged and clamped for boring, or a single double-spread plate may be securely clamped throughout almost its entire length.

As the clamping plates 34 moved by the worm gears are forced toward the opposing clamping members 34 and are tightened against the parallel edges of the one or two electrotypes 30, the electrotypes are forced radially outward into firm contact with the concave surface of the work holder l4 thereby accurately conforming the electrotypes to the desired curvature and insuring that the finished thickness of the electrotypes is In order to prevent damage to the printing surface of the electrotypes 30, provision is usually made for a thickness of softer material, such as a sheet of heavy, hard paper, between the electrotype and the concave face of the work holder l4, and by varying the thickness of this sheet of paper, deviations from a standard electrotype thickness may be easily obtained with great accuracy.

The several series of holes 44 provide for a coarse adjustment of the position of the clamping plates on one side of the work holder I4, While the worm-gear-moved clamping plates 34 at the other side of the work holder allow for even minute dimensional differences in the arcuate length of the plates and insure that any size of plate, within the capacity of the work holder, may be accurately and securely clamped.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom within the scope of the accompanying claim Without departing from the principles of the invention and without sacrificing its chief advantages.

What is claimed is:

In a machine for boring and interiorly finishing curved printing plates, a work holder comprising a hollow, parti-cylindrical form having a plurality of spaced parallel arcuate slots extending from each edge thereof, two pairs of spaced work engaging clamps movable circumferentially of said slots, curved to fit the inside surface of the work holder, the clamps of each pair being movable in arcuate paths towards and from each other, means for locking one of each pair of clamps in any one of several different positions to form Work engaging abutments and to predetermine the position of the work, and means for powerfully moving and locking the other clamp of each pair to force and hold an arcuate printing plate against said abutments, whereby said printing plate may be securely clamped between each of said pairs of clamping members.

GEORGE W. BUNGAY.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,255,279 Beckman Feb. 5, 1918 1,269,239 Wood June 11, 1918 1,942,593 Claybourn Jan. 9, 1934 

